Decreased expression of angiotensin-converting enzyme in the airway epithelium of asthmatic subjects is associated with eosinophil inflammation

Citation
Gl. Roisman et al., Decreased expression of angiotensin-converting enzyme in the airway epithelium of asthmatic subjects is associated with eosinophil inflammation, J ALLERG CL, 104(2), 1999, pp. 402-410
Citations number
39
Categorie Soggetti
Clinical Immunolgy & Infectious Disease",Immunology
Journal title
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
ISSN journal
00916749 → ACNP
Volume
104
Issue
2
Year of publication
1999
Part
1
Pages
402 - 410
Database
ISI
SICI code
0091-6749(199908)104:2<402:DEOAEI>2.0.ZU;2-V
Abstract
Background: Angiotensin-converting enzyme (ACE) is a peptidase involved in the metabolism of several bioactive peptides. It may be involved in the air way inflammation and hyperresponsiveness that occur in asthma. Objective: We studied the expression of ACE in the airway mucosa of normal and asthmatic subjects and assessed the relationship between ACE expression and airway inflammation and bronchial hyperresponsiveness in asthma. Methods: We used immunohistochemistry to study the ACE expression and airwa y inflammation in bronchial biopsy samples obtained by fiberoptic bronchosc opy from 20 asthmatic subjects randomly assigned to groups treated with (n =10) or without inhaled corticosteroids (n = 10) and from normal subjects ( n = 10). Airway response to methacholine and bradykinin was also determined for all subjects. Results: In normal subjects ACE was present in the surface epithelium, the endothelial cells of the lamina propria, and the submucosal glands, in whic h ACE was found in seromucous cells and in secreted mucus. ACE was not dete cted in smooth muscle cells and in most of the endothelial cells of the vas cular network surrounding the glands. ACE was absent or present at lower le vels in the surface epithelium of asthmatic subjects not treated with corti costeroids compared with those treated with corticosteroids and the control group. In asthmatic subjects low levels of ACE in the epithelium were asso ciated with larger numbers of eosinophils in the epithelium and lamina prop ria. There was no relationship between ACE levels in the airway mucosa and airway responsiveness to methacholine and bradykinin. Conclusion: ACE expression is decreased in the epithelium of asthmatic pati ents and is associated with increased eosinophil inflammation.